In general, there are a very large number of LED strips in a large-sized liquid crystal display device, and the power consumed thereby is also considerably high. When the large-sized liquid crystal display device operates in a three-dimensional scan mode, the LED strips, from top to bottom, are divided into a plurality of backlight partitions, and each of the backlight partitions contains an identical quantity of LED strips. The LED strips in one backlight partition are actuated by one or more related LED backlight drive units. In other words, the LED strips actuated by one LED backlight drive unit are gathered into one and the same backlight partition. When the backlight partitions are scanned, from top to bottom, in the liquid crystal display device one by one, the backlight partitions emit light respectively in terms of transmission of a three-dimensional image display signal. Moreover, the LED strips in only one backlight partition may emit light at every turn and are powered by a correlated LED backlight drive unit for lightening, whereas the rest of the LED backlight drive units are all under a suspended state. Such an operating manner may lead to a localized high temperature in a backlight drive circuit, so that heat throughout an entire backlight module is distributed unevenly, which is very likely to cause damage to circuit elements. In addition, since there are always several LED backlight drive units under the suspended state, the efficiency of the entire backlight drive circuit is inevitably low.